LIVRE JDG 2010

The prosthetic geometry will as such influence

the way the kinematic pattern is presented by its

tibiofemoral contact points. As shown in figure

3, the initial motion arc from full extension to

30° of flexion will induce a much greater trans-

lation of the tibiofemoral contact points than the

motion arc between 100° and 130° flexion, due

to the ‘flatter’ nature of the femoral prosthetic

component in its most caudal aspect as compa-

red to its posterior aspect (fig. 3). Consequently

direct comparison of graphs obtained from the

native knee with graphs obtained from the pros-

thetic knee is not possible, unless the same

methodology for studying and reporting the

kinematic pattern is used. We recently publi-

shed on an experimental model allowing the

comparative study of the native knee with the

prosthetic knee [19]. This model allows for a

direct comparison between the native and pros-

thetic setting and provides information to ans-

wer the following questions that are commonly

asked regarding this subject.

COMPARATIVE KINEMATICS BETWEEN THE NATIVE KNEE AND TOTAL KNEE ARTHROPLASTY

167

Fig. 2 : A model fitting technique based upon fluoroscopic imaging allows for kinematic

description of the prosthetic knee. Contact points are derived indirectly from the relative

distance between tibia and femur.

Fig. 3 : Graphical representation of sequential relative

tibiofemoral position during the flexion arc.